Jul 12 – 23, 2021
Europe/Berlin timezone

Measurement of the Proton-Air Cross Section with Telescope Ar-rays Black Rock, Long Ridge, and Surface Array in Hybrid Mode.

Jul 14, 2021, 6:00 PM
1h 30m


Poster CRI | Cosmic Ray Indirect Discussion


Rasha Abbasi (Loyola University Chicago-Physics Department)


Ultra High Energy Cosmic Ray (UHECR) detectors have been reporting on the proton-air cross section measurement beyond the capability of particle accelerators since 1984. The knowledge of this fundamental particle property is vital for our understanding of high energy particle interactions and could possibly hold the key to new physics. The data used in this work was collected over eight years using the hybrid events of Black Rock (BR) and Long Ridge (LR) fluorescence detectors as well as the Telescope Array Surface array Detector (TASD). The proton-air cross section is determined at √s= 73 TeV by fitting the exponential tail of the Xmax distribution of these events. The proton-air cross section is then inferred from the exponential tail fit and from the most updated high energy interaction models. σ inel p−air is observed to be 520.1±35.8 [Stat.]+25.3−42.9[Sys.] mb. This is the second proton-air cross section work reported by the Telescope Array collaboration.


Proton-air cross section, Ultra High Energy Cosmic Rays.

Subcategory Experimental Results
Collaboration Telescope Array

Primary authors

Rasha Abbasi (Loyola University Chicago-Physics Department) Dr William Hanlon (The Smithsonian Astrophysical Observatory)

Presentation materials